Oil well safety device



Aug- 12, l952 c. 1 .WH1GHAM OIL WELL SAFETY DEVICE.

Filed Nbv. 7, 1949 2 SHEETS-SHEET l I* #el l..

f l I.

Aug. 12, 1952 c. L.. WHIGHAM 2,606,619

OIL WELL 4SAFETY DEVICE 2 SHEETS-SHEET 2 Filed Nov. '7, V1949 lill; A

INVENTOR 2m l.. Wfl/HAM ATTORNEYS Patented Aug. 12, 1952 UNITED sTATssPATENT o-Frlcef Carl L. Whigham, Odessa, Tex.

Application November 7, 1949, Serial No. 125,914

8 Claims. V(Cl. 16S-14) 1. This invention relates to an oilwell safetydevice.

As is well known, it is necessary to service oil wells in various ways.For example, it is necessary from time to time to swab the well tubing,I

and this is done by connecting swabs to a rope socket connected to aline or cable which is reciprocated to raise and lower the swabrepeatedly in the well tubing. The reciprocation of the swab is underthe manual control of an operator, and it is the common practice toconnect a nag to the cable, orotherwise mark a cable a given distancefrom the swab as a warning signal to show that the swab is nearing thetop of the well. Very frequently, an operator will fail to see the flag,thus allowing the rope socket to be pulled up against the oil saver,causingy the line to break and allowing theswab to fall back to thebottom of the well. It is then necessary to perform the annoying andtime-consuming job of fishing the swab from the well.

An important object of the present invention is to provide a novelsafety device which automatically prevents a swab or other servicingtool from dropping into a well if the operator negligently permits thetool to be pulled upwardly too far with the resultant breaking of theline.

A further object is to provide such a device in combination with a wellhead whereby, in the event the line is broken, the well tubing can beclosed olf and the device removed therefrom, carrying the tool and thebroken line connected thereto, thus permitting the sealing oil" ci theengaged by the gripping means, whereby theV device may be disconnectedfrom the well for the servicing of the tube, Vfor example, for thereplacement of worn swab rubbers.

, 2 parts of the device and adjacent elements being shown in section,

Figure 2 is an enlarged transverse sectional view on line 2-2 of Figure1,

Figure 3 is an enlarged vertical longitudinal sectional view .throughthe present device `showing portions of adjacent elements withl a wellswab or similar tool shown in dotted lines, and

Figure 4 is a fragmentary View similar to Figure 3 showing theoperationof the means for limiting upward movement of arope socket associatedwith a well servicing tool.V

Referring to Figure .1, rthe numeral II] designates a conventional wellhead l'as-'a whole comprising the usual elementsforming a part of suchstructure and which need not be illustrated in detail. The well headincludes the usualV master Other objects and advantages of the inventionwill become apparentduring the course of the following description.

In the drawing, I have shown one embodiment of the invention. `In thisshowing, f I 1 Figure 1. is a side elevation of aconventional well headand oil saver, the present inventionbeing shown in position relativefthereto and valve II operated by a `hand wheel I2. At the top of thewell head is connected the usual eliminator I3. 1

The present device is indicated as a whole by the numeral I5 and isconnected at its lower end in a manner to be describedto the eliminatorI3, while the upper end of the device is connected as described below toa conventional oil saver I6. The device I5 comprises a sleeve I8externally threaded at its lower end as at I9 for connection with theeliminator I3. At its` upper end, the sleeve I8 is internally threadedas at 29 for connection with the reduced lowerend 2l of a connector 22forming` a part-of the present device as will become apparent below. Theupper end of the-connector 22 is internally threaded as at 23 forthreaded connection with the depending lower end 24 of the oil saver.

The sleeveA I8 has a tapered bore 29 diverging upwardly andv terminatingatits lower lend approximately at the point 29. Below such point, thebore is cylindrical. A' y A pair of complementary slips 35i is arrangedin the tapered bore 28. These slips are divided diametrically as shownin Figure 2 and theedges 3l of the slips are in proximity to `each otherwhen the slips are at their lower limits of movement. At such limits ofmovement, the, lower extremities of the slips aresubstantiallyVcoincident with the point 29. lrlhe slipsshave their outer facestapered to correspond tothe taper of the bore 23, and they have theirinner faces serrated -as at 32 to provide teeth adapted to grip thetool` or part thereof Yas further referred to below. Y I

Theswabbing of an oil well is-accornplished by connecting swabbing tools35to-a line socket 3G connected yatits upper endto aflineor cable 3lrextending upwardly through a reduced opening 38 in the connector 22,thence upwardly through the oil saver for connection with the usualapparatus employed under the control of the operator for verticallyreciprocating the swabs. The line socket 36 is provided with a reducedupper neck portion 40 into which the line 31 extends to be connected tothe socket.

Near its lower end, the sleeve I8 is provided with diametricallyopposite screws 42 threaded through the casing I8 and provided with jamnuts 43. These screws are normally inoperative and are turned inwardlyunder conditions referred to below to limit upward movement of thesocket 36 to prevent engagement of the latter with the teeth of theslips 30.

Operation The swabbing operation is carried on in the usual conventionalmanner, the vertical reciprocation of the swab being under the controlof the operator. If, through carelessness. or negligence, the operatorfails to reverse 'the direction of reciprocation as the socketV 36 movesupwardly and before it strikes the bottom of the connector 22, suchstriking will frequently result in the breaking of the line or cable 31.With the present device, it will be noted that the internal diameter ofthe slips 3U is slightly less than the external diameter of the socket36. As the socket moves upwardly under the conditions referred to, itwill engage the teeth 32 of the slips and these elements will moveupwardly over the tapered surface 28. 'I'his operation diametricallyseparates the slips to a suiiicient extent for the movement of thesocket 36 therebetween.

If the line 31 then breaks, the spring 33, urging the slips downwardly,causes the teeth 32 to grip and hold the socket 36, thereby preventingits falling downwardly into the bottom of the' well. The present devicethereby prevents the necessity for having to fish the tool from thewell.

Thereafter, assuming that the wellis flowing, the rubber'packing (notshown) conventionally used in the oil saver I6, is tightened around thecable 31 to prevent oil or gas leakage. The eliminator I3 is thentightened to they swab stem to prevent leakage therearound, whereuponthe sleeve I8 is unscrewed from the eliminator I3 and raised togetherwith the swab stem through the eliminator until the swab reaches thebottom of the latter. The master valve II is then closed, whereupon theeliminator, swab, swab stem, and the present device are lsafely removedfrom the well head, the well being kept under control by the closing ofthe valve II; The broken line and swab are removed, whereupon theYdevice is replaced with a new swab therein to continue the operation'.

When the swab is being pulled out tovl replace worn swab rubbers, whichis necessary several times during a day of swabb-ing, the screws 42 areturned inwardly approximately two turns, which places the ends'of thescrews ,a distance apart closer than the diameter of the socket 36 belowthe neck 40, which will prevent the socket 36 from moving Vupwardly intoengagement with the slips 36. The eliminator is then unscrewed from thewell head, and lifted out, the eliminator, the present device and theVVoil saver beingrernoved intact. After the swab rubbers 'have beenreplaced, the swabl is set back in the well tubing andlet down untiltheeliminator reaches-the well'head. The eliminator is screwed into placeand the bolts 42 are backed out the necessary distance to clear thesocket 36, whereupon the device is ready for the continued swabbing ofthe well. The jam nuts 43 are employed at the inner and normal positionsof the screws 42 to lock these screws against movement.

From the foregoing, it will be apparent that the present device greatlyfacilitates the servicing of wells by preventing automatically thedropping of a tool such as a swab into a well. It also will be apparentthat the present device may be easily handled for removal andreplacement, and that its use in combination with the conventionalelements of an oil well permits the latter to be kept under `control atall times. The escape of oil and gas may be completely prevented, thuseliminating the usual fire hazard.

I claim:

l. A well safety device comprising a stationary vertical sleeve adaptedto be xed above and in alignment with a well and having an upwardlydiverging bore, a plurality of complementary slips having outer facesfitting said bore and inner serrated faces, a member fixed to the upperend of said sleeve and having a reduced axial opening therethrough forthe passage of the cable of a servicing tool, said opening being smallerthan the tool, a compression spring between said member and said slipsurging the latter downwardly, and an oil saver above and connected tothe upper end of said sleeve by said member.

2. In combination with a well and a servicing col suspended from a cablefor vertical movement in the well, a sleeve at the upper end of the wellin alignment therewith, said sleeve having an upwardly diverging taperedbore, a plurality of complementary slips in said bore and having taperedouter faces fitting said bore, said slips having inner surfaces adaptedto grip the tool, when pulled upwardly to a predetermined extent toenter said slips, to prevent downward movement of the tool, a gas savermounted above said sleeve and through which the cable extends, aconnecting member between` the upper end of said sleeve and said gassaver for fixing the latter relative to said sleeve, said connectingmember having an axial opening smaller than the tool and through whichthe cable extends, and a compression spring between saidconnectingmember and the upper ends of said slips for urging the latterdownwardly.

3. In combination with a well having a well head at the upper endthereof, an oil saver spaced above said well head, and a well servicingtoo-l having a cable connected thereto for moving the tool vertically inthe Well, a sleeve fixed at its lower end to said well head and havingan upwardly diverging tapered bore, a plurality of complementary slipsin said bore having outer surfaces fitting said bore and inner grippingsurfaces dening an opening slightly smaller than said tool whereby thelatter, as it moves upwardly beyond a predetermined point, engages suchslips to move them upwardly and enter thereinto to prevent downwardmovement of the tool into the well, and a connecting member carried bysaid sleeve at the upper end thereof and to which said oil saver is Xedthereabove, the cable extending upwardly through said connecting memberand through the oil saver.

il. The combination set forth in claim 3 wherein said `connecting memberis provided with an axial guide opening through which the cable extends,vand a compression springbetween said connecting member andthe upper endof said slips to urge thelatter downwardly. F

5. The combination set forth in claim 3 wherein said connecting memberis provided with an axial guide opening through which the cable extends,and a compression spring between said connecting member and the upperend of said slips to urge the latter downwardly, the. tool having areduced upper end and said sleeve being provided below said slips withradial screws movable inwardly to engage the tool below the reduced endthereof upon upward movement of the too1 to prevent the latter fromentering said slips.

6. In combination with a well having a well head provided with a mastervalve, an eliminator fixed tothe top of said well head, an oil saverspaced above said eliminator, a well servicing tool, and a cableconnected to said tool to reciprocate it in the well, a vertical sleevein axial alignment with the well and xed at its lower end to saideliminator, said sleeve having `an upwardly divergng tapered bore, aplurality of complementary Slips in said bore having outer faces taperedto correspond to the taper of said bore and fitting therein, said slipshaving serrated inner surfaces defining an opening through the slipsslightly smaller than the tool, whereby the latter, when it movesupwardly beyond a predetermined point, engages said slips to move themupwardly and enter thereinto to be gripped by said serrated surfaces toprevent downward movement of the tool, a connecting member carried bythe upper end of said sleeve and to which the oil saver is xedthereabove, said connecting member having a reduced guide openingthrough which the cable extends to pass through the oil saver, and acompression spring between said connecting member and the upper ends ofsaid slips to urge said slips downwardly, the tool, when engaged by saidslips, being arranged wholly above said master valve whereby the lattermay be closed to seal the well for the removal of said sleeve with thetool therein.

7. The combination set forth in claim 6 wherein the upper end of thetool is reduced, and radial screws carried by said sleeve beneath saidslips and adapted to be turned inwardly to engage the tool below thereduced end thereof to prevent the entrance of the tool into said slips.

8. In combination with a well having a well head connected to the upperend thereof and including a master valve, and a well servicing toolhaving a cable from which the latter is suspended for vertical movementin the well, said tool having a reduced upper end, a sleeve in verticalalignment with the well and xed at its lower end to the well head, saidsleeve having an upwardly diverging tapered bore, a plurality ofcomplementary slips in said bore having outer surfaces fitting saidbore, said slips having inner gripping surfaces defining an opening ofslightly less diameter than the tool whereby the latter, as it movesupwardly above a predetermined point, will move said slips upwardly andenter th-ereinto to 4be gripped by said inner surfaces to preventdownward movement o-f the tool, a member fixed to the upper end of saidsleeve and having an openingr therethrough for the passage of the cable,a compression sp-ring between said y member and the upper ends of saidslips to urge the latter downwardly, the tool, when supported by saidslips, being arranged wholly above said master valve whereby the lattermay be closed to seal the well while said sleeve and the tool carriedthereby is removed from said wellhead, and radial screws carried by saidsleeve and movable inwardly to engage the tool below said reduced end toprevent the too-l from moving into said slips.

CARL L. WHIGHAM.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,825,004 Livergood Sept. 29,1931 2,109,546 McLagan Mar.1, 1938 2,241,333 Smith May 6, 1941 2,306,617Dick Dec. 29, 1942 2,354,929 Rector et al Aug. 1, 1944 2,482,455 BaileySept. 20, 1949

